Date of Award

Spring 2026

Document Type

Open Access Dissertation

Department

Electrical Engineering

First Advisor

Guoan Wang

Second Advisor

Xiaofeng Wang

Abstract

The increasing demand for higher data rates, greater computational performance, and continued PCB miniaturization has rendered interconnects a critical bottleneck in modern communication and computing systems. High-density routing, while enabling compact designs, significantly exacerbates signal integrity (SI) challenges such as impedance mismatch, far-end crosstalk (FEXT), and propagation delay. Despite advances in design practices, efficient closed-form analytical models capable of accurately characterizing complex, high-frequency interconnect geometries remain limited, necessitating reliance on computationally intensive numerical simulations. This dissertation addresses these limitations by developing analytical modeling methodologies and proposing novel interconnect structures to ensure robust SI in high-speed PCB systems.

The first part of this dissertation develops closed-form, equation-based models for complex coupled and curved stripline structures, including geometries with tab features and advanced CuMax routing. To enable accurate modeling of curved coupled striplines in dense routing environments, the electric field compliant geometrical discretization (ECGD) model is introduced. The proposed models demonstrate high accuracy and computational efficiency, as validated against Ansys HFSS simulations and experimental measurements.

Building upon these methodologies, the second part of the dissertation presents an extended closed-form analytical framework for trace-crosstalk-through-antipad (TCTA) structures. A key contribution is the development of a novel physical model for multilayer coupled striplines incorporating antipads. This model enables accurate computation of S-parameters for three-dimensional, via-inclusive routing configurations, thereby addressing a critical analytical gap in existing literature. The accuracy and efficiency of the proposed model are confirmed through validation against Ansys HFSS simulation results.

High-density routing is further shown to suffer from pronounced SI degradation due to impedance discontinuities and, in particular, FEXT arising from electromagnetic coupling between adjacent traces—a problem exacerbated at increasing data rates. In the final part of this dissertation, an “LL” shaped defected tabbed routing structure is proposed to mitigate FEXT. This structure is analyzed using an equivalent circuit model and validated through experimental measurements. However, the incorporation of defected and tabbed features introduces additional propagation delay. To address this limitation, a second novel coupled-line structure incorporating an embedded metasurface is introduced. This structure is likewise analyzed via an equivalent circuit model and experimentally validated, demonstrating substantial FEXT reduction while maintaining ultra-low latency.

Overall, the analytical methodologies and novel interconnect structures developed in this dissertation provide effective solutions for FEXT suppression in high-speed PCB interconnects. These contributions offer significant potential for optimizing SI and advancing the design of next-generation computing and communication systems.

Rights

© 2026, Yingcong Zhang

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